Endorphins are released when a person is in pain, during starvation, and during exercise. Researchers are now looking at ways to utilize this response to alleviate chronic pain. Studies have shown that acupuncture may relieve pain by stimulating the release of endorphins. A food substance related to endorphins is phenylethylamine, found in chocolate. Chocolate has always been a highly valued commodity in many cultures, and there is some evidence that chocolate may improve mood temporarily due to its high levels of sugar and fat, phenylethylamine, and caffeine. The sugar in chocolate is associated with a release of the neurotransmitter serotonin, and the fat and phenylethylamine are associated with an endorphin release. This combination produces an effect that has been called “optimal brain happiness.” The caffeine in chocolate adds a temporary stimulant effect. This may explain why some people crave chocolate when they’re feeling depressed.